Ever since the Transantiago overhaul, public transporation in Santiago has been, to put it politely, a bear. There's a whole long story about what's going on and what was promised and how the information was disseminated and how bad the crush is during rush hours. For a great discussion of what the metro looks (and feels) like during rush hour, I send you to Margaret's blog, Cachando Chile, where she give her impressions, as well as explains different concepts of personal space. There's some interesting stuff in the comments as well. Go! Then come back.
To be honest, when in Santiago, I mostly get around by bike. In fact, as soon as I finish here, I will strap on my helmet, (though sadly, not my ipod, because at least this month I've had a stern talking to myself about how dangerous that is), and set out to the asphalt. I know this is not practical or desirable for everyone, and if you're not feeling it, I won't hassle you about it, especially if you live, as I do, in a small space, and don't want to turn your living room/satellite kitchen/office into that plus bicycle parking.
But I will remind you that even though you might not have thought of South America as a great place to take to the underground, you'd be plenty surprised. Santiago's metro is gorgeous, if overpopulated, and some (ha! me!) might call it the Cadillac of metros, a line I stole from my sister when she was telling me how great her (pre move to the 'burbs) grocery pushy-cart was. The Santiago metro's even nicer than that cart. And a bit faster, I'd think. Though not faster than my memory which pulled that back from the early nineties to the present day. Now that's fast. Go neurons.
So for more info on metros in South America, go read the article here. And don't forget to stumble it, shower me with attention and praise for giving up on the música while riding, at least for this week.
Oh! and before I go, one downside to biking where you need to go is that even I, multitasker extraordinaire, have still not figured out how to read and pedal at the same time.